The Somatic Indel Detector can be run in two modes: single sample and paired sample. In the former mode, exactly one input bam file should be given, and indels in that sample are called. In the paired mode, the calls are made in the tumor sample, but in addition to that the differential signal is sought between the two samples (e.g. somatic indels present in tumor cell DNA but not in the normal tissue DNA). In the paired mode, the genotyper makes an initial call in the tumor sample in the same way as it would in the single sample mode; the call, however, is then compared to the normal sample.